Speedo adjusting?

[sunhuntin]

ive been wondering about the accuracy of my speedo for a while, so tested it against a "your speed is" sign. i went past with my needle exactly on 50. the sign told me speed was 45! is it possible to have the speedo adjusted so its accurate? i tried upping my speed by 5, but it was impossible to keep it steady and watch the road at the same time.

cheers!!

[grusomhat]

If it's not cable driven then you can install a speedhealer. They aren't cheap, but can come with wiring harnesses for most bikes for a plug and play type deal. They will fix the speed but mess up the odo. It's a case of compromise as manufactures build in an error in speed but the odometer reading is fairly accurate so fixing the speed, makes the odo out.

You can also pick up speed correctors from JayCar but you need to know how to wire them up.

[sunhuntin]

its cable driven i think. no computers on my bike, lol. shes not flash enough for that, hehehe. thanks though!

[Virago]

Bike speedos are notoriously inaccurate, generally over-reading like yours. 10% is par for the course I'm afraid, Mutley's 250 Virago is the same.

[Clivoris]

Bike speedos are notoriously inaccurate, generally over-reading like yours. 10% is par for the course I'm afraid, Mutley's 250 Virago is the same.

Get an Aprilia. Officially timed at 254kmh. Speedo read 256kmh.

[PrincessBandit]

Same with both my bandit and Balu's burgman. We have fun seeing how our speeds compare with the GPS unit we sometimes use while we're out. Anything from 5 - 8 kph discrepancy depending - somewhere about 7 - 8 % according to Mr Mathmetician Balu!

[Warr]

3 options come to mind.
1. Put-up with it
2. Buy a push bike electronic speedo. They can all be programmed to different wheel sizes & can give you other useful info like ride average speed etc. Can be tricky mounting the wheel magnet tho.
3. Get a GPS

[grusomhat]

My KR is 20% out which I consider to be pretty bad. Just put up with it and mark on your speedo what normal speeds should be, like 50, 70, 100. Otherwise bike speedos are great but don't read above 99kmh usually.

[p.dath]

Note that bikes of European origin often have a deliberate 7% error built in. This is because in Europe manufacturers aren't allowed to make a speedo that tells you you are going faster than you actually are. So to fix this problem, they make them deliberately say you are going 7% faster than you really are.

Very noticable in BMW cars as well ... If you have a GPS then it is really obvious.

[p.dath]

Oh, and the error only affects the speedo, not the odometer. The odometer is still correct.

[sil3nt]

All vehicles are like this. Car magazines usually publish real speed at indicated 100kph and its usually around 95kph.

Just get a bicycle computer and use that. You can get wireless ones.

[MotoKuzzi]

its cable driven i think. no computers on my bike, lol. shes not flash enough for that, hehehe. thanks though!

I don't know if it's possible on a motorcycle but I once had a hot rod speedo corrected by the addition of a ratio box made by some outfit in Hamilton. Basically a little box with a couple of gears connected into the cable which alters the speed of the cable at the speedo end.

[Mully]

A lot of those "your speed is..." signs are out as well. I wouldn't take a reading off those as gospel.

Use a GPS and mark 50, 70 and 100km on your speedo.

[p.dath]

All vehicles are like this. Car magazines usually publish real speed at indicated 100kph and its usually around 95kph.

Just get a bicycle computer and use that. You can get wireless ones.

I haven't had that experience with vehicles not from Europe.

For example, my Holden Commodore says exactly the same speed as my GPS reports.
I'm sure Ford XR6 and XR8's will be the same.

[AllanB]

What a lot of hard work you lot are suggesting. I have a much simpler plan.

Ride like a mad bastard and eventually the police will tell you exactly how fast you were travelling at